openzipkin/zipkin: technical due diligence, read from its repository

81 product files are in the new language and 23 are still in the old one, 73 months after the first new file appeared. The new language's share of the lines rose from 1% to 78%, and moved 0 percentage points in the last year. Two languages for one job doubles what an engineer has to know, and the unmoved half is usually what nobody wants to touch. Ask whether finishing it is planned, and what it costs.

Deleted lines per line added rose from 0.59 to 1.20 between the first and second halves of this history. Rework is normal and often healthy, but a rising ratio means an increasing share of the team's time is spent replacing code that already exists rather than building what does not. Whether that is deliberate repayment or churn is a question for the team.

7 places in product code build SQL by formatting or joining strings rather than passing parameters. In each, what the code shows going in is a table or column name, a constant, or something the line does not show, not a request's value. Ask whether any value reaches these strings, rather than a parameter.

The newest was published on 2026-08-28. A project that publishes advisories is telling its users about its fixes, and the count and pace say how much security work it carries. Whether 1 of them are fixed in the code you ship could not be told from this history: its version is only known to be at least 3.6.1. Answer lives in: the release you run, set against each fixed version. The record is incomplete: NVD: 2 records name zipkin with nothing tying them to this repository (CVE-2026-41310, CVE-2026-81870).

Nothing in the service initialises an error reporter (Sentry, Rollbar, Bugsnag, Honeybadger or an APM agent). An exception in production reaches a person only if someone is reading the logs, which usually means a customer reports it first.